On 11/1/19 12:22 PM, Srinivas Kandagatla wrote:
On 01/11/2019 16:39, Pierre-Louis Bossart wrote:
+static int qcom_swrm_prepare(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+
+ if (!ctrl->sruntime[dai->id])
+ return -EINVAL;
+
+ return sdw_enable_stream(ctrl->sruntime[dai->id]);
So in hw_params you call sdw_prepare_stream() and in _prepare you
call sdw_enable_stream()?
Shouldn't this be handled in a .trigger operation as per the
documentation "From ASoC DPCM framework, this stream state is linked to
.trigger() start operation."
If I move sdw_enable/disable_stream() to trigger I get a big click
noise on my speakers at start and end of every playback. Tried
different things but nothing helped so far!. Enabling Speaker DACs
only after SoundWire ports are enabled is working for me!
There is nothing complicated on WSA881x codec side all the DACs are
enabled/disabled as part of DAPM.
that looks like a work-around to me? If you do a bank switch without
anything triggered, you are most likely sending a bunch of zeroes to
your amplifier and enabling click/pop removals somehow.
It'd be worth looking into this, maybe there's a missing digital
mute/unmute that's not done in the right order?
Digital mute does not help too, as they get unmuted before
sdw_enable_stream() call in trigger, I hit same click sound.
Same in the disable path too!
Also I noticed that there are more than 20+ register read/writes in the
sdw_enable_stream() path which took atleast 30 to 40 milliseconds.
wow, that's a very slow command bandwith, is this because of a low frame
rate or the SLIMbus transport in the middle?
At any rate, we've got to improve the bank switch. The intent of the
alternate banks is that software mirrors the register settings in the
background and only updates what needs to be changed during the
enable/disable part. when you operate with a fixed clock frequency
usually it's only the channel enable that changes so it could be very
fast (1 write deferred to the SSP point).
On the intel side our command bandwidth is comparable with the usual
I2C/HDaudio codecs, but still things complicated and slower than they
should be. I have been chasing a bug happening on bank switches in
multi-stream configurations for 10+ days and it's quite hard to debug at
the moment.
One possibility is to use regmap for the banked registers, and a manual
mirroring after each bank switch. Or maybe we could even have an
extension of regmap to do this for us.
I will try my luck checking the docs to see if I can find something
which talks about this.
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